WIND POWER

The Wind energy is the energy generated by the wind and can be used directly or be transformed as electric power. You can apply this energy on a large scale, being one of the most productive renewable energies or in small installations. It is currently the fastest growing renewable energy and represents a large portion of the electricity production. This kind of has a lot of potential and a great number of applications. The installation of an aerogenerator in a windy region, allows the production of electricity for a remote home, to pump water, or for any other isolated application for which electricity is needed.

We owe the first electricity generating wind turbine to Charles F. Brush (1849-1929), one of the founders of the American electric industry. It was a giant of 144 blades made out of cedar wood. It functioned for 20 years and charged the batteries in the basement of his mansion. In the 50´s the first alternating current turbines were developed. The first oil crisis (1973) generated a real interest in wind energy. The generation of wind turbines of 55 kW of 1980, represented the technological and industrial boom for the modern aerogenerators.

This energy consists of generating electricity by means of wind mills that move a turbine. The aerogenerator, normally, has three blades connected to a rotor that activates an electric generator. That´s what we see placed at the top of the mast of a typical aerogenerator. It is achieved through the kinetic energy produced by this movement. When the wind blows at double speed, eight times more energy is generated. The power of the generator is in function to the length of its blades, the greater the length, the greater power is obtained and consequently, more electricity is generated.

This kind of energy seems to be the one that has the most future of all the renewable energies, along with solar energy. It can be used, like solar power, to generate electricity in remote areas, where connections to the power grid do not exist or it can be sold to the electric company. Just like the photovoltaic system it is the most simple and economic way to get water to farm lands isolated from the electric grid, using the most appropriate technology for agricultural development.

The size of the aerogenerators can vary, from units that start at 400w and blades with a diameter of 3 m. to commercial aerogenerators installed by large companies that reach 2.5MW of power and blades of 80m in diameter. Every aerogenerator needs a minimum starting speed, which is 11km/h for this type. It´s biggest productivity is with winds around 45km/h, but if the wind reaches 100km/h, they stop running automatically, to avoid damaging the unit

The use of this type of energy is only applicable in very windy areas, with wind almost every day of the year and an average wind speed of above the fore mentioned of 11km/h, as the minimum for the aerogenerator to start working.

It´s quite common to combine this type of energy with photovoltaic solar energy, since the necessary weather conditions for both technologies are complementary. Sun and wind, together, are not usually combined very often.

We can emphasize that wind energy is generated indirectly thanks to the Sun. The sun heats the air and this causes the currents that generate wind. Wind is inexhaustible, and is renewed on a continuous basis. Winds are therefore variable, and so is wind energy production.

The wind power  is becoming increasingly less expensive, as the technology advances. It allows progress without hurting the Earth, respecting the environment. It does not cause any type of contamination. It can be obtained, in greater o smaller degree, everywhere.

The offshore wind farms

Most wind power turbines are still installed on land, but the future could lie on offshore. Wind speeds over oceans are on average twice as high as over land, making offshore wind parks an interesting alternative, but technically a more challenging alternative. The biggest technical problem is that wind energy cannot be produced just anywhere; average wind speeds must be good enough to make installing a turbine cost-effective.

The future of wind energy development in Europe and worldwide is undoubtedly the offshore wind farm. Spain is the second European country in installed wind power. In 2006, Spain had a total of 11,730 MW of capacity installed on its mainland. The new offshore wind farms will be built on sites along Spain's 4000-kilometer-long coast under a license scheme. With significant own technology, now Spain is preparing to begin the development of offshore technology with the release of specific legislation and an environmental analysis of the entire national coastline.

Research has shown that Spain has great potential for getting energy from offshore wind turbines.”Spain is a peninsula with sea on three sides and so is one of the best places in the world for building wind farms at sea”.  Studies indicate that offshore wind parks could generate between 3,000 and 7,000 terawatt-hours (TWh)/a year in the seas of European countries as a whole and 140 and 500 TWh/a year in the seas of Spain.

Spain -- the world's second leading producer of wind power -- has passed a new law allowing wind parks to be built off its coast. It is predicted that the offshore wind parks will generate between 2,000 and 3,000 megawatts (MW) of electricity by 2020. That would represent a major contribution to Spain's future wind power production.

Offshore wind energy is taking off in the Spanish panorama. After several years with limited activities in this field, the present situation is moving on, and there are several indicators to be optimistic about future developments in Spain. The new regulation of the procedures, conditions and criteria for authorizations of permissions for the construction of offshore wind power plants, establish a simplified procedure for offshore wind installations. Spanish Ministry of Industry has undertaken a study of the coastline to identify the best sites for building wind turbines and to assess the impact of wind parks on the landscape.

In the middle of 2009 there were only 1500 wind megawatts installed into the sea. Although the first offshore wind farm experiment took place in 1990, most of the facilities built up to now since then were pilot projects. These statements show the incipient of offshore wind power. At this moment, however, the boom of offshore wind energy finally seems to be happening. There are a few countries at the top of current offshore wind energy development (United Kingdom, Denmark, Holland, Sweden, Germany; followed at a distance by a few others, Spain, France, etc). This current situation, the row materials problem and the general commitments to reduce the emission of greenhouse gases are leading to predict a promising future for offshore wind power.

The trend towards the introduction of wind farms in deep water has led to designs that are prototypes today, but certainly given the energy crisis it will soon be available, many countries already provide for the development of  offshore wind.The Spanish resource for offshore wind power plants seems to be enormous, but the main barrier is that waters are deep waters, that require new technology to be developed. Spanish industries and research centers are working in this direction.

At present there is no offshore farm in Spain. The Canaries are one of the best places in Spain in terms of value of the resource and they  have to look to the offshore wind as an opportunity to extract energy without occupying valuable and scarce land, using own resource and diversifying the energy basket.

This is primarily to establish the search criteria of areas, and have been divided into three categories: Technical, Environment and Territorial. Firstly we have to find places   where technically wind farms could be located because of the resort, with little depth and access to coast to be viable. The second filter will be the environmental analysis for protecting sites in the sea or in coast.

Bathymetry will have to determine the depth of each zone. At present, there are parks more of 40 m deep, so it has defined the height of 50m in the first instance, but in the near future will be possible to descend deeper. Only in the electrical systems of Lanzarote, Fuerteventura and Gran Canaria offshore wind farms could be installed, but not with current technology, since we are talking about areas where the depth exceeds fifty meters, with less than two hundred meters.

The benefits of offshore wind farms are the not occupation of land, high value of the resource and less  turbulence. The drawbacks are the high cost and difficulty installation and maintenance. Wind turbines - large or small - are not always welcome additions to the landscape. Many people find them loud and unsightly. They are also known to disrupt electro-magnetic communication signals. Others claim that turbines endanger wildlife, particularly birds, though this is disputed.

Concerns about the impact of off shore wind parks on Spain's thriving tourist industry have been one reason why the construction of wind turbines has been restricted to the country's mainland.

Wind energy development in the Canary Islands

The level of concentration of carbon dioxide (CO2) in the atmosphere is expected to be twice as high by the middle of the 21st century as the value registered during the pre-industrial epoch if the current trend of emitting pollutants to the atmosphere continues. The reduction of these agents is of paramount importance and it is an essential objective in the agenda of the international political and scientific community.

Among the most significant efforts, the production and more efficient use of the energy resources and an increment of the use of Renewable Energy for the production of electric energy are fundamental. These aims have a greater priority in the context of the Canary Islands, where the shortage of conventional energy resources increases outside energy dependence in the maintenance of regional economic development. The tourist situation in the Canary Islands, with an annual income of around 9 millions of tourists, also makes it necessary to generate energy from clean sources on the archipelago, taking into account the excellent conditions existing on the islands for the development of Renewable Energy.

The local government recognizes that the RE represents a strategic sector for the development of the islands, awarding of the necessity of overcoming the insular barriers for the implementation to large scale of the RE, especially in the regulation environment.

Eventhough the Spanish Canary Islands are an isolated  archipelago of seven small islands, they have devoted local resources to investigating the best ways to move wind power into the future. They hope to serve as an example for islands and rural communities around the world.
“In the Canary Islands, the grids are weaker than in Europe, and there are islands around the world with even weaker grids,” says AEE director Alberto Ceña. “The challenge is how to integrate wind with diesel engines or fuel engines. We still need to work a lot on that. The experience of the Canary Islands is going to be very useful in the future of wind power.”
In fact, the islands were, along with Tarifa on Spain’s southernmost border, the site of the country’s first wind farms in the early 1990s. Development slowed, but the local parliament’s 2006 decision to produce 25 per cent of the region electricity from renewable energy by 2015 spurred an increase in development.

The Canary Islands Institute of Technology (ITC), a regional government research center, has continued working to develop systems that look ahead to the island’s future. “The Canary Islands are a real laboratory and can serve as the ideal platform for testing new energy technologies,” says ITC director Gonzalo Piernavieja.

One recent project involves the island of El Hierro, which has a population of 10,500. The government recently announced a plan that would enable the island to derive 100 percent of its power from renewable sources. The key will be 10 megawatts of wind power connected to a pump system. When wind blows so fiercely that locals can’t utilize all the energy, the extra power will be used to pump water up a nearby mountain to two reservoirs, one of which is a natural volcanic crater. When the wind drops, the water will fall and turn a turbine. This pumping system has been paired with other forms of electricity, but it’s never been used with wind power before. In addition, the entire system will be connected to a desalination plant to provide potable water. The dimensions of El Hierro make this small, windy, mountainous desert island the perfect laboratory for testing the new system.

 And as the Canary Islands work to become a model for islands and rural areas internationally, so Spain—and Spanish companies—hope to show the world just what the wind might bring.